DYNAMIC TENSILE PROPERTIES OF IRON AND STEELS FOR A WIDE RANGE OF STRAIN RATES AND STRAIN

摘要

The tensile stress-strain curves of iron and a variety of steels, covering a wide range of strength level,over a wide strain rate range on the order of 10~(-3) -10~3 s~(-1), were obtained systematically by using the Sensing Block Type High Speed Material Testing System (SBTS, Saginomiya). Through intensive analysis of these results, the strain rate sensitivity of the flow stress for the large strain region, including the viscous term at high strain rates, the true fracture strength and the true fracture strain were cleared for the material group of the ferrous metals. These systematical data may be useful to develop a practical constitutive model for computer codes, including a fracture criterion for simulations of the dynamic behavior in crash worthiness studies and of work-pieces subjected to dynamic plastic working for a wide strain rate range.